﻿using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Demo3
{
    class Shape
    {
        private string color;
        private double a;
        public string Color { get => color; set => color = value; }
        public double A { get => a; set => a = value; }

        public virtual void GetArea(double a)
        {

        }
    }
}
